1. Field of the Invention
The present invention relates to a 2D/3D image switching display device, and more particularly to a 2D/3D image switching display device capable of switching a display status to the display of planar images or stereo images.
2. Description of the Related Art
The principle of present well-known stereo image display technologies adopts a binocular disparity for receiving different images from both left and right eyes of a user respectively, and finally the user's brain merges the images into a stereo (3D) image. In naked-eye stereo display technologies, there are two main types of structures, respectively: lenticular lens and barrier, and these structures have advantages and disadvantages, wherein the lenticular lens includes a plurality of slender straight convex lenses arranged continuously along an axial direction to produce different views to the left and right eyes by the principle of optical refraction. Compared with the barrier, the lenticular lens makes use of the light refraction to achieve the light division effect, so that there will be less loss of light and better brightness, but the refraction occurred at edges of the lens is restricted and the refraction effect is poor, or stray light is produced due to factors such as the manufacturing discrepancy of the lenticular lens and the difficulty of leveling a lens surface, and thus blurring a portion of a stereo image and affecting the overall display effect of the stereo image. In addition, the barrier uses a whole row of obstacles to limit the emission of lights at a certain angle and allows viewing images of a certain angle to be transmitted to the left and right eyes to produce the stereo image. Compared with the lenticular lens, the single lens image is clearer, but the congenital structural characteristic will result in drawbacks such as reducing the overall brightness and the resolution of the image.
In addition, the general stereo display device can display stereo images only, but cannot switch between planar images and stereo images, and the main reason resides on that after the lenticular lens or barrier is combined with the general display device, and all planar images passed through lenticular lens or barrier are divided into left-eye images and right-eye images, unless a stereo image display module is installed externally. If it is not necessary to display stereo images, the external stereo image display module is removed from the display device. However, the aforementioned application requires a precious alignment to avoid a reduced image resolution or a deviation. Therefore, manufacturers have developed a stereo image display device capable of switching the display between stereo images and planar images.
As disclosed in R.O.C. Pat. No. M371902 entitled “Display device for switching 2D image/3D image display screen”, the display device comprises a flat panel display and a parallax barrier panel installed on a display surface of the flat panel display, wherein the parallax barrier panel includes a grid pattern having a first electrochromic material layer and a second electrochromic material layer. In 2D image display status, the grid pattern, the first electrochromic material layer and the second electrochromic material layer are transparent, and in a 3D image display status, the grid pattern is an opaque pattern, and the first electrochromic material layer has a first color, and the second electrochromic material layer has a second color.
As disclosed in R.O.C. Pat. No. M368088 entitled “Integrated electrochromic 2D/3D display device”, the display device comprises: a first substrate; a parallax barrier unit installed under a first substrate; a color filter unit installed under the parallax barrier unit; a common electrode disposed under the color filter unit; a liquid crystal unit installed under the common electrode; a plurality of thin film transistors installed under the liquid crystal unit; a second substrate disposed under plurality of liquid crystal units; and a light source installed under the second substrate, wherein the parallax barrier unit modulates planar images and stereo images to reduce the thickness and assembling cost of the conventional display device.
The aforementioned two patented technologies adopt parallax barrier devices with an electrochromic material to display stereo images, but both structures have a common drawback of lacking a necessary electrolyte layer of the electrochromic device, since ions are not supplied to the electrolyte layer of the electrochromic layer, and the electrochromic device cannot produce a reversible oxidation or reduction to complete the change of coloration or decoloration, or the coloration/decoloration speed is very slow, so that the aforementioned patent technologies are not feasible in practical applications. In addition, the transparent electrode layer and the electrochromic material layer of the parallax barrier device are grid patterned, and whose manufacturing process requires a precise alignment to achieve the effect of coating, spluttering or etching each laminated layer, and thus the manufacturing process becomes very complicated. In addition, all laminated layers are grid patterned, so that a hollow area is formed between one grid and the other, and the overall penetration, refraction and reflection of the light will be affected. Even for the general 2D display, the video display quality of the display device will be affected adversely to cause problems related to color difference and uneven brightness. In another structure embedded with a liquid crystal display substrate in accordance with the R.O.C. Pat. No. M368088 is installed on an insulating transparent material by a grid pattern method. Although this patented technology can reduce the thickness of a stereo image liquid crystal display, yet the actual manufacturing procedure is also very complicated. Furthermore, the aforementioned prior arts come with a multilayer laminated structure, and thus the overall brightness and quality of the 3D images will be affected adversely for both 2D and 3D image displays.